Astronomers have spotted a planet that is the closest potentially habitable world humanity has ever seen.

The planet is four times as big as Earth and sits perfectly within
the “Goldilocks zone” that would make it able to support life.
Astronomers look for worlds that that sit in that perfect region, where
it is not too hot or cold to support liquid water.

It is one of the first times that astronomers have spotted a planet
near to us that has the kind of rocky, solid surface that is thought to
be necessary for alien life.

"It is a particularly exciting find because all three planets are of
low enough mass to be potentially rocky and have a solid surface, and
the middle planet, Wolf 1061c, sits within the 'Goldilocks' zone where
it might be possible for liquid water — and maybe even life — to exist,"
said lead study author Dr Duncan Wright in a statement.

"It is fascinating to look out at the vastness of space and think a
star so very close to us — a near neighbour — could host a habitable
planet.”

Scientists might now be able to catch a view of the planet, helping
them study its atmosphere and explore whether it might be able to
support life.

The team found three planets going around a star that is stable like
our own but smaller and relatively cool. One of the three planets, known
as Wolf 1061c, sits squarely within the habitable zone.

The team, from the University of New South Wales (UNSW), made the
discovery using the HARPS spectrograph, which is part of the European
Southern Observatory's 3.6 metre telescope in La Silla in Chile.

"Our team has developed a new technique that improves the analysis of
the data from this precise, purpose-built, planet-hunting instrument,
and we have studied more than a decade's worth of observations of Wolf
1061," Professor Chris Tinney, head of the Exoplanetary Science at UNSW
group, said in a statement.

"These three planets right next door to us join the small but growing
ranks of potentially habitable rocky worlds orbiting nearby stars
cooler than our Sun."

Scientists will now hope that they can explore the planet’s atmosphere in more detail.

"The close proximity of the planets around Wolf 1061 means there is a
good chance these planets may pass across the face of the star. If they
do, then it may be possible to study the atmospheres of these planets
in future to see whether they would be conducive to life," said team
member UNSW's Dr Rob Wittenmyer in a statement.